Evaluation of a rapid immunochromatographic test for the diagnosis of intestinal protozoan infections among patients attending a rural outreach outpatient department in Northern India

Despite great efforts, intestinal protozoan infections remain a significant healthcare concern worldwide. Although many point-of-care (POC) tests are increasingly being used, microscopic examination of stool specimens remains the mainstay for their diagnosis, especially in resource-limited settings. We assessed the utility of rapid POC tests based on immunochromatography among patients from rural Northern India. A total of 78 patients were enrolled in the study. Out of nine specimens that tested positive for Giardia duodenalis on microscopy, an immunochromatographic test (ICT) could detect only five (55.55%). Entamoeba histolytica/dispar was demonstrated in two specimens on microscopy, both of which were missed by ICT. Its overall sensitivity, specificity, and positive and negative predictive value were 50%, 98.5%, 83.3%, and 93%, respectively. Its performance was considered unsatisfactory. Although ICT-based tests provide a relatively rapid and less labor-intensive alternative, they should be used to supplement and not replace stool microscopy.

Severe lophomoniasis in a patient with diabetes and past history of COVID-19 in Central Iran: case report

In this case report, we address the diagnostic challenges and clinical implications of severe infection with Lophomonas blattarum in a patient initially suspected of experiencing long COVID symptoms. We describe the patient's medical history, initial symptoms, diagnostic tests, and treatment. A female patient with diabetes in her early 60s presented with severe shortness of breath and was initially diagnosed with diabetic ketoacidosis (DKA). After resolution of her DKA symptoms, persistent respiratory issues led to a COVID-19 test, which was negative. A chest computed tomography scan revealed abnormalities, prompting bronchoscopy and bronchoalveolar lavage fluid analysis, which confirmed the presence of L. blattarum. Notably, the protozoan remained mobile and viable even after a 4-day transport at ambient temperature. This case emphasizes the importance of considering alternative diagnoses and improving awareness about L. blattarum infection in patients with respiratory symptoms, for timely and accurate management.

Lophomonas as a respiratory pathogen-jumping the gun

Human infections with the protozoan Lophomonas have been increasingly reported in the medical literature over the past three decades. Initial reports were based on microscopic identification of the purported pathogen in respiratory specimens. Later, a polymerase chain reaction (PCR) was developed to detect Lophomonas blattarum, following which there has been a significant increase in reports. In this minireview, we thoroughly examine the published reports of Lophomonas infection to evaluate its potential role as a human pathogen. We examined the published images and videos of purported Lophomonas, compared its morphology and motility characteristics with host bronchial ciliated epithelial cells and true L. blattarum derived from cockroaches, analyzed the published PCR that is being used for its diagnosis, and reviewed the clinical data of patients reported in the English and Chinese literature. From our analysis, we conclude that the images and videos from human specimens do not represent true Lophomonas and are predominantly misidentified ciliated epithelial cells. Additionally, we note that there is insufficient clinical evidence to attribute the cases to Lophomonas infection, as the clinical manifestations are non-specific, possibly caused by other infections and comorbidities, and there is no associated tissue pathology attributable to Lophomonas. Finally, our analysis reveals that the published PCR is not specific to Lophomonas and can amplify DNA from commensal trichomonads. Based on this thorough review, we emphasize the need for rigorous scientific scrutiny before a microorganism is acknowledged as a novel human pathogen and discuss the potential harms of misdiagnoses for patient care and scientific literature.

The Application of 3base™ Technology to Diagnose Eight of the Most Clinically Important Gastrointestinal Protozoan Infections

Globally, over 3.5 billion people are infected with intestinal parasites each year, resulting in over 200,000 deaths. Three of the most common protozoan pathogens that affect the gastrointestinal tract of humans are Cryptosporidium spp., Giardia intestinalis, and Entamoeba histolytica. Other protozoan agents that have been implicated in gastroenteritis in humans include Cyclospora cayetanensis, Dientamoeba fragilis, Blastocystis hominis, and the microsporidia Enterocytozoon bieneusi and Encephalitozoon intestinalis. Genetic Signatures previously developed a 3base™ multiplexed Real-Time PCR (mRT-PCR) enteric protozoan kit (EP001) for the detection of Giardia intestinalis/lamblia/duodenalis, Cryptosporidium spp., E. histolytica, D. fragilis, and B. hominis. We now describe improvements to this kit to produce a more comprehensive assay, including C. cayetanensis, E. bieneusi, and E. intestinalis, termed EP005. The clinical performance of EP005 was assessed using a set of 380 clinical samples against a commercially available PCR test and other in-house nucleic acid amplification tests where commercial tests were not available. All methods provided at least 90% agreement. EP005 had no cross-reactivity against 82 organisms commonly found in the gut. The EP005 method streamlines the detection of gastrointestinal parasites and addresses the many challenges of traditional microscopic detection, resulting in cost savings and significant improvements in patient care.

Infectious Optic Neuropathies

PURPOSE OF REVIEW

This article reviews common infectious optic neuropathies, focusing on the more common and globally important entities.

RECENT FINDINGS

Novel infections continue to emerge and drift geographically over time; not infrequently, these have important neurologic or ocular features. Malarial retinal findings comprise a relatively specific set of findings and serve as an invaluable aid in the diagnosis of cerebral malaria. Therapy continues to evolve and is best formulated in concert with an infectious disease expert.

SUMMARY

Infectious optic neuropathies are less common than inflammatory or ischemic optic neuropathies; may present with varied, overlapping, and nonspecific clinical appearances; and comprise an important differential consideration demanding specific therapy.

Increasing the Efficiency of Spontaneous Sedimentation for the Diagnosis of Intestinal Protozoa

The aim of this study was to evaluate the association between a longer sedimentation time, the reading of a larger number of slides, and the collection of multiple samples on the efficiency of the spontaneous sedimentation technique. Twenty-two patients with a previous parasitological exam positive for intestinal protozoa were recruited to collect new fecal samples (3 samples per patient) before the beginning of antiparasitic treatment. All collected fecal samples were used for spontaneous sedimentation and centrifuge-flotation techniques. Of these, all 22 patients were positive based on spontaneous sedimentation, and 59.1% (13/22) based on centrifuge flotation. The number of samples and the number of slides analyzed by spontaneous sedimentation influenced the number of positive cases. The modifications applied to the spontaneous sedimentation technique increased its performance in protozoa diagnosis.

Easyscreen™ Enteric Protozoa Assay For the Detection of Intestinal Parasites: A Retrospective Bi-Center Study

Gastroenteritis caused by single or multiple pathogens remains a major diagnostic challenge for the laboratory, as diagnosis is achieved using different techniques with variable sensitivity and specificity. The aim of this study was to evaluate the EasyScreen™ Enteric Protozoa Detection Kit, a multiplex PCR assay for the detection and identification of the 5 most common protozoan parasites in fecal samples. A total of 632 fecal samples, submitted for routine screening to 2 centers in north-eastern Italy, was included in the study. The results of the molecular assay were compared to those of the standard diagnostic procedures, represented by microscopy and immunoassays. Out of 32 samples testing positive by conventional tools, 31 were detected as concordantly positive using the EasyScreen Kit. Additionally, 91 out of 632 samples only tested positive by the molecular test, therefore increasing the positive detection rate by 275%. Finally, the EasyScreen assay detected 14 co-infections compared to 3 co-infections identified by conventional methods. The EasyScreen Kit provided a rapid and sensitive simultaneous identification of the most important diarrhea-causing protozoa that infect humans. Additionally, this molecular assay presents several advantages compared to conventional tools, such as the standardization and near-total automation of the process. Although critical issues related to the employment of molecular assays are still evident, the system is suitable for clinical parasitological diagnosis as long as it is used in association with conventional tools.

Risk factors for childhood enteric infection in urban Maputo, Mozambique: A cross-sectional study

BACKGROUND

Enteric infections are common where public health infrastructure is lacking. This study assesses risk factors for a range of enteric infections among children living in low-income, unplanned communities of urban Maputo, Mozambique.

METHODS & FINDINGS

We conducted a cross-sectional survey in 17 neighborhoods of Maputo to assess the prevalence of reported diarrheal illness and laboratory-confirmed enteric infections in children. We collected stool from children aged 1-48 months, independent of reported symptoms, for molecular detection of 15 common enteric pathogens by multiplex RT-PCR. We also collected survey and observational data related to water, sanitation, and hygiene (WASH) characteristics; other environmental factors; and social, economic, and demographic covariates. We analyzed stool from 759 children living in 425 household clusters (compounds) representing a range of environmental conditions. We detected ≥1 enteric pathogens in stool from most children (86%, 95% confidence interval (CI): 84-89%) though diarrheal symptoms were only reported for 16% (95% CI: 13-19%) of children with enteric infections and 13% (95% CI: 11-15%) of all children. Prevalence of any enteric infection was positively associated with age and ranged from 71% (95% CI: 64-77%) in children 1-11 months to 96% (95% CI: 93-98%) in children 24-48 months. We found poor sanitary conditions, such as presence of feces or soiled diapers around the compound, to be associated with higher risk of protozoan infections. Certain latrine features, including drop-hole covers and latrine walls, and presence of a water tap on the compound grounds were associated with a lower risk of bacterial and protozoan infections. Any breastfeeding was also associated with reduced risk of infection.

CONCLUSIONS

We found a high prevalence of enteric infections, primarily among children without diarrhea, and weak associations between bacterial and protozoan infections and environmental risk factors including WASH. Findings suggest that environmental health interventions to limit infections would need to be transformative given the high prevalence of enteric pathogen shedding and poor sanitary conditions observed.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02362932.

EPIDEMIOLOGY OF CLOSTRIDIUM DIFFICILE INFECTION IN HOSPITALISED PEDIATRIC PATIENTS IN GEORGIA

Clostridium difficile, a Gram-positive spore-forming bacillus, is the most common identifiable etiologic agent of antibiotic-associated diarrhea. The incidence of Clostridium difficile infections among hospitalized children has been increasing across the world. The aim of our study was to evaluate occurrence of Clostridium difficile and some other gastrointestinal pathogens among hospitalized pediatric patients in Georgia, as far as currently statistical data on the topic is very limited in the country. One of the objectives of the study was to test and pilot the real-time Polymerase Chain Reaction diagnostic systems for rapid and simultaneous identification of number of pathogens with a particular emphasis on diarrheal disease diagnostics as these are one of the primary public health priorities in Georgia and worldwide. Cross-Sectional study has been performed on 211 samples collected from 192 pediatric patients. Two pediatric hospitals were involved in the study: M. Iashvili Children's Central Hospital and Tbilisi Children's Clinical Hospital for Infectious Diseases. Laboratory investigations were done in the Clinic NeoLab, Tbilisi, Georgia. Study materials collected for testing were stool samples. Samples were tested by EIA kits (CerTest biotec, Zaragoza, Spain) for presence of A/B toxin according to the manufacturer's instructions. EIA test positive samples were analyzed by home-made multiplex real-time polymerase chain reaction (NeoPCR Diagnostics, NeoLab, Tbilisi, Gerogia) for confirmation of the infection and for simultaneous identification of additional gastrointestinal pathogens including Entamoeba histolitica, Giardia lamblia, Cryptsporidium parvum, Adenovirus, Rotavirus, Norovirus and Astrovirus. All samples were also tested for the presence of the above listed pathogenic agents using the same type EIA kits as for Clostridium difficile described above (CerTestbiotec, Zaragoza, Spain) for presence of the corresponding pathogen. The average age of the study participants was 3.5 years, 56.7% were male and 43.3% were female patients. Presence of Clostridium difficile have been documented in 21 samples out of 211 (10%). Besides the Clostridium difficile, other enteric pathogens have been revealed with the following frequencies: Rotavirus in 12 cases (5.7%), Adenovirus in 11 (5.2%), Giardia lamblia in 10 (4.7%), Astrovirus in 3 (1.4%), Cryptsporidium parvum in 3 (1.4%), Entamoeba histolitica in 2 (0.9%), Norovirus in 2 (0.9%). 49 samples were from out-patient cases (2 samples were positive for Clostridium difficile) and 162 samples were from in-patient cases (19 samples were positive for Clostridium difficile). Clostridium difficile is the frequent pathogenic agent causing diarrheal disease among hospitalized pediatric patients. Development of Clostridium difficile related diarrhea is associated with the antibiotic treatment of pediatric patients hospitalized due to different clinical diagnosis. Targeted early detection of these pathogens is important for the optimal management of diarrheal infection in pediatric patient which will lead to the better clinical outcome and reduction of morbidity rate among hospitalized pediatric patients.

COMPARISON OF IMMUNOCHROMATOGRAPHIC TEST AND MICROSCOPY IN THE DETECTION OF SOME ENTERIC PROTOZOA IN STOOL SAMPLES

Infection with pathogenic intestinal protozoa. as Giardia lamblia,, Entamoeba histolytica and Cryptosporidium parvum cause considerable gastrointestinal morbidity, malnutrition and mortality worldwide, especially among young children in developing countries. The present study was carried out on 71 cases (44 males & 27 females) chosen from Pediatric and Internal Medicine Inpatient and Outpatient Clinics of Zagazig University Hospitals, complaining of different gastrointestinal troubles with an age range of 6-60 years. Also, 20 apparently healthy individuals (11 males & 9 females) cross matched were considered as a control negative group. All stool samples were examined by direct wet smears, concentration techniques, staining of the smears using trichrome stain and Modified Ziehl-Neelsen method. Copro-antigen detection in faecal sample was by using quick immunochromatographic test. A total of 71 cases suffering from different GIT manifestations showed G. lamblia (30.7%), Cryptosporidium parvum (19.8%), EntamoebahistolyticalE. dispar (11%) and mixed infection of three protozoa (6.6%). However, by copro-antigen G. lamblia was positive in (31.8%) of C. parvum in (20.9%); E. histolytica/E. dispar in (11%) of cases. Immunochromatography/copro-antigen test recorded sensitivity and spec- ificity of (100%) and (96.6%) respectively in G. lamblia detection. For C. parvum, sensitivity was (100%) and specificity was (97.1%) while for E. histolytica/E. dispar. sensitivity and specificity were (100%) for both. Immunochromatographic assay proved to be simple, easy and useful in confirming absence or the presence of intestinal protozoan infection in clinically suspected cases with negative stool examination.

Diagnosis of Persistent Fever in the Tropics: Set of Standard Operating Procedures Used in the NIDIAG Febrile Syndrome Study

In resource-limited settings, the scarcity of skilled personnel and adequate laboratory facilities makes the differential diagnosis of fevers complex [1–5]. Febrile illnesses are diagnosed clinically in most rural centers, and both Rapid Diagnostic Tests (RDTs) and clinical algorithms can be valuable aids to health workers and facilitate therapeutic decisions [6,7]. The persistent fever syndrome targeted by NIDIAG is defined as presence of fever for at least one week. The NIDIAG clinical research consortium focused on potentially severe and treatable infections and therefore targeted the following conditions as differential diagnosis of persistent fever: visceral leishmaniasis (VL), human African trypanosomiasis (HAT), enteric (typhoid and paratyphoid) fever, brucellosis, melioidosis, leptospirosis, malaria, tuberculosis, amoebic liver abscess, relapsing fever, HIV/AIDS, rickettsiosis, and other infectious diseases (e.g., pneumonia). From January 2013 to October 2014, a prospective clinical phase III diagnostic accuracy study was conducted in one site in Cambodia, two sites in Nepal, two sites in Democratic Republic of the Congo (DRC), and one site in Sudan (clinicaltrials.gov no. NCT01766830). The study objectives were to (1) determine the prevalence of the target diseases in patients presenting with persistent fever, (2) assess the predictive value of clinical and first-line laboratory features, and (3) assess the diagnostic accuracy of several RDTs for the diagnosis of the different target conditions.

Waterborne Pathogens: The Protozoans

Waterborne diseases associated with polluted recreational and potable waters have been documented for more than a century. Key microbial protozoan parasites, such as Cryptosporidium and Giardia, are causative agents for gastrointestinal disease worldwide. Although not a first-line diagnostic approach for these diseases, medical imaging, such as radiography, computed tomography, magnetic resonance imaging, ultrasonography, and nuclear medicine technologies, can be used to evaluate patients with long-term effects. This article describes protozoan pathogens that affect human health, treatment of common waterborne pathogen-related diseases, and associated medical imaging.

Detection of Tritrichomonas Foetus by Polymerase Chain Reaction in Cultured Isolates, Cervicovaginal Mucus, and Formalin-Fixed Tissues from iNfected Heifers and Fetuses

A rapid, reliable polymerase chain reaction (PCR) assay, originally developed for definitive laboratory identification of the bovine venereal pathogen Tritrichomonas foetus from cultures of male reproductive tract fluids, was used for testing the following: 1) cultured, geographically disparate trichomonad isolates, 2) formalin-fixed tissues from infected heifers and naturally infected fetuses, and 3) cervicovaginal mucus (CVM) from experimentally infected females. In 12 of 12 Western Hemisphere isolates of pathogenic T. foetus (isolated from outbreaks of clinical trichomoniasis or from screening surveys) and in 1 of 1 American Type Culture Collection strain of Tritrichomonas suis, PCR yielded a positive result, i.e., a 347—base pair amplicon in the 5.8S ribosomal RNA and internal transcribed spacer (5.8S—ITS) region of the genome, whereas cultures of Trichomonas vaginalis and Trichomonas gallinae did not produce a PCR product. The PCR assay was also positive in formalin-fixed, paraffin-embedded endometrial samples from 4 of 4 experimentally infected heifers, as well as in archived tissues from 2 of 2 T. foetus—infected aborted bovine fetuses that were submitted to the diagnostic laboratory from a natural outbreak. It was negative in fixed, embedded uterine tissues of 2 of 2 uninfected virgin heifers used as negative controls and in archived fixed gut tissue of a T. gallinae—infected pigeon. In another experiment, CVM aspirated from 4 of 4 experimentally infected heifers in the fifth or sixth postinfection week yielded a positive PCR product of the expected size, whereas CVM from 2 of 2 controls were PCR negative. Pending validation in larger clinical studies, the PCR assay for the 5.8S—ITS coding region of the T. foetus genome offers the prospect of definitive identification of this agent directly from CVM or from formalin-fixed tissues or when false-positive culture results are suspected.

Identification criteria of the rare multi-flagellate Lophomonas blattarum: comparison of different staining techniques

Bronchopulmonary lophomoniasis (BPL) is an emerging disease of potential importance. BPL is presented by non-specific clinical picture and is usually accompanied by immunosuppression. Culture of Lophomonas blattarum is difficult and its molecular diagnosis has not yet been developed. Therefore, microscopic examination of respiratory samples, e.g., bronchoalveolar lavage (BAL) or sputum, is the mainstay of BPL diagnosis. Creola bodies and ciliocytophthoria are two forms of bronchial cells which occur in chest diseases with non-specific clinical picture like that of BPL. Both forms could be misrecognized as multi-flagellates because of their motile cilia in the wet mounts and due to shape variability of L. blattarum in stained smears. The aim of the study is to compare different staining techniques for visualizing L. blattarum to improve the recognition and diagnosis of BPL, to distinguish respiratory epithelial cells from L. blattarum and to decide which stain is recommended in suspected cases of BPL. BAL samples from patients which contain L. blattarum, creola bodies, and ciliocytophthoria were collected then wet mounts were examined. The BAL samples were also stained by Papanicolaou (PAP), Giemsa, hematoxylin and eosin (H & E), trichrome, Gram, and Diff-Quik (DQ) stains. The different staining techniques were compared regarding the stain quality. In wet mounts, the ciliary movement was coordinate and synchronous while the flagellar movement was wavy and leaded to active swimming of L. blattarum. In stained slides, bronchial cells were characterized by the presence of basal nucleus and the terminal bar from which the cilia arise. Trichrome was the best stain in demonstration of cellular details of L. blattarum. H & E, PAP, and Giemsa stains showed good quality of stains. Gram and DQ stains showed only pale hues of L. blattarum. We recommended adding Wheatley's trichrome staining to the differential diagnosis workup of cases of non-specific chest infections, especially when BPL is suspected, to avoid overdiagnosis or underdiagnosis of it.

[A first case report of empyema caused by Tetratrichomonas species in Japan]

Trichomonad is a type of flagellate that parasitizes the human oral cavity, intestine, or vagina. However, respiratory infection is rare. We report a patient with pyothorax related to Tetratrichomonas species, which is the first reported case in Japan. The patient was a 66-year-old female. She consulted the Emergency Outpatient Unit of our hospital with fever, dyspnea, and the retention of pleural effusion. The appearance of the pleural effusion collected by thoracic drainage was brown, fetid pus. On microscopy, Trichomonad was detected in the pleural effusion. On a gene test, Tetratrichomonas sp. was identified. Based on this experience, we propose that non-stained specimens should be examined to detect Trichomonad on a puncture fluid test. (Case report).

Comparison between Quantitative Buffy Coat (QBC) and Giemsa-stained Thin Film (GTF) technique for blood protozoan infections in wild rats

The quantitative buffy coat (QBC) technique and conventional Giemsa thin blood smear was compared to determine the sensitivity and specificity of the technique in detecting blood parasitic infection of the rodent populations from four urban cities in Peninsular Malaysia. A total of 432 blood samples from four rat species (Rattus norvegicus, Rattus rattus diardii, Rattus exulans and Rattus argentiventer) were screened using both techniques and successfully detected two blood protozoan species (Trypanosoma lewisi and Plasmodium sp.) with Trypanosoma lewisi predominantly infecting the population. Results showed that Giemsa-stained thin film (GTF) was the better detection method on blood parasitemia (46.7%) compared to Quantitative Buffy Coat method (38.9%) with overall detection technique sensitivity and specificity at 83.2% and 74.8% respectively. The sensitivity in detection of Trypanosoma lewisi was 84.4% with value slightly lower for Plasmodium sp. infections at 76.6%. Statistical analysis proved that GTF technique was significantly more sensitive in the detection of blood protozoan infections in the rodent population compared to QBC (p<0.05).

High-throughput vector-borne disease environmental surveillance by polymerase chain reaction according to international accreditation requirements

Although vector-borne diseases are specific to the region of the host, there is a necessity for surveillance or reference laboratories to perform standardized, high-throughput testing capable of meeting the needs of a changing military environment and response efforts. The development of standardized, high-throughput, semiquantitative real-time and reverse transcription real-time polymerase chain reaction (PCR) methods allows for the timely dissemination of data to interested parties while providing a platform in which long-term sample storage is possible for the testing of new pathogens of interest using a historical perspective. PCR testing allows for the analysis of multiple pathogens from the same sample, thus reducing the workload of entomologists in the field and increasing the ability to determine if a pathogen has spread beyond traditionally defined locations. US Army Public Health Command Region-Europe (USAPHCR-Europe) Laboratory Sciences (LS) has standardized tests for 9 pathogens at multiple life stages. All tests are currently under international accreditation standards. Using these PCR methods and laboratory model, which have universal Department of Defense application, the USAPHCR-Europe LS will generate quality data that is scientifically sound and legally defensible to support force health protection for the US military in both deployed and garrison environments.

[A study on the differential diagnosis of ciliated epithelial cells from Lophomonas blattarum in bronchoalveolar lavage fluid]

OBJECTIVE

To validate the authenticity of the cases diagnosed as pulmonary Lophomonas blattarum infection in literatures and Lophomonas blattarum as a kind of pathogen resulting in pulmonary infection.

METHODS

From June 2012 to May 2013, mobile cells with cilia at the anterior end of the cells were observed in BALF from 6 patients with pulmonary disease in our hospital. Morphological feature and ultrastructure of the cells were further investigated by optical microscope and electron microscope to determine the type of the cells referring to literature-published photos of Lophomonas blattarum. Literatures about Lophomonas blattarum infection were searched with keyword Lophomonas blattarum from Wanfang Data, China National Knowledge Infrastructure (CNKI) and PubMed. Diagnostic methods and figures provided by the literature were carefully reviewed, and the accuracy of diagnosis of pulmonary Lophomonas blattarum was identified.

RESULTS

Mobile cells found in BALF from the 6 patients in our hospital had the morphological features of bronchial ciliate epithelial cells. A nucleus far from the cilia was observed in the middle or at the bottom of the cytoplasm, and these cells did not display the characteristic cytological structures of Lophomonas blattarum: calyx, perinuclear tubules and axial filament. Diagnosis of pulmonary Lophomonas blattarum reported in literatures so far were all based on the morphological features of mobile cells with a cluster of flagellate at anterior end of the cell by optical microscopy. None of the authors did further exploration on the ultrastructure of such a kind of cells and compared with features of Lophomonas blattarum described in the literature. All the active cells reported in literatures had the identical morphological features to those found in our investigation.

CONCLUSION

In the past 20 years, all the diagnosed cases as pulmonary Lophomonas blattarum infection reported in our country were misdiagnosed. Currently, there is no evidence to show Lophomonas blattarum as a pathogen resulting in pulmonary infection.

Intestinal protozoan parasitic infection among school children

BACKGROUND

Intestinal protozoan parasitosis is highly prevalent among general population, majority of them are children. The objective of the study is to find out the prevalence of intestinal protozoan infection in school children of Sindhuli.

METHODS

Stool samples were collected from school children of Sindhuli in June 2011 and investigated in National Institute of Tropical Medicine and Public Health Research, Laboratory by using formal-ether concentration method. Statistical significance was analyzed by using Chi-Square test.

RESULTS

A total of 342 stool samples were collected and 68 (19.8%) protozoan parasites were identified. The prevalence rate of protozoa in boys and girls were 16.9% and 22.0% respectively. Altogether 5 species of protozoan parasites were detected. Of them Entamoeba coli was most common followed by Giardia lamblia, Entamoeba histolytica, Blastocystis hominis and Endolimax nana. Positive rate was highest in Dalit (20.3%), and least in Indo-Aryan (19.6%).

CONCLUSIONS

There is a low prevalence of intestinal protozoan parasitosis among children even though this study emphasizes the need for improved environmental hygiene i.e. clean water supplies and enhanced sanitation.

Enteric protozoa in the developed world: a public health perspective

Several enteric protozoa cause severe morbidity and mortality in both humans and animals worldwide. In developed settings, enteric protozoa are often ignored as a cause of diarrheal illness due to better hygiene conditions, and as such, very little effort is used toward laboratory diagnosis. Although these protozoa contribute to the high burden of infectious diseases, estimates of their true prevalence are sometimes affected by the lack of sensitive diagnostic techniques to detect them in clinical and environmental specimens. Despite recent advances in the epidemiology, molecular biology, and treatment of protozoan illnesses, gaps in knowledge still exist, requiring further research. There is evidence that climate-related changes will contribute to their burden due to displacement of ecosystems and human and animal populations, increases in atmospheric temperature, flooding and other environmental conditions suitable for transmission, and the need for the reuse of alternative water sources to meet growing population needs. This review discusses the common enteric protozoa from a public health perspective, highlighting their epidemiology, modes of transmission, prevention, and control. It also discusses the potential impact of climate changes on their epidemiology and the issues surrounding waterborne transmission and suggests a multidisciplinary approach to their prevention and control.

Parasitic infections in HIV infected individuals: diagnostic & therapeutic challenges

After 30 years of the human immunodeficiency virus (HIV) epidemic, parasites have been one of the most common opportunistic infections (OIs) and one of the most frequent causes of morbidity and mortality associated with HIV-infected patients. Due to severe immunosuppression, enteric parasitic pathogens in general are emerging and are OIs capable of causing diarrhoeal disease associated with HIV. Of these, Cryptosporidium parvum and Isospora belli are the two most common intestinal protozoan parasites and pose a public health problem in acquired immunodeficiency syndrome (AIDS) patients. These are the only two enteric protozoan parasites that remain in the case definition of AIDS till today. Leishmaniasis, strongyloidiasis and toxoplasmosis are the three main opportunistic causes of systemic involvements reported in HIV-infected patients. Of these, toxoplasmosis is the most important parasitic infection associated with the central nervous system. Due to its complexity in nature, toxoplasmosis is the only parasitic disease capable of not only causing focal but also disseminated forms and it has been included in AIDS-defining illnesses (ADI) ever since. With the introduction of highly active anti-retroviral therapy (HAART), cryptosporidiosis, leishmaniasis, schistosomiasis, strongyloidiasis, and toxoplasmosis are among parasitic diseases reported in association with immune reconstitution inflammatory syndrome (IRIS). This review addresses various aspects of parasitic infections in term of clinical, diagnostic and therapeutic challenges associated with HIV-infection.

[Aetiology of intestinal parasites in a sample of students from Mozambique]

The purpose of this survey is to assess the prevalence of intestinal parasites in a population of Mozambican students. Ninety five faecal samples were collected at the three schools in Marrere, Mozambique, for a period of about one week. Observations of fresh and Giemsa-stained samples were performed at the laboratory of the Geral de Marrere Hospital; observation after concentration (FEA) was performed later at the Microbiology Laboratory of the S. Maria Nuova Hospital (Reggio Emilia, Italy). The results show a high rate of intestinal parasites among the subjects examined, supported mainly by helminths (Strongyloides stercoralis and Ancylostoma/Necator americanus), and protozoa (Dientamoeba fragilis and Giardia intestinalis). Analysis of data shows that the search for pathogenic parasites with the formalin-ethyl acetate (FEA) stool concentration technique shows higher sensitivity than the observation of fresh samples (60% vs 30%) and in some cases allows the presence of a second or third parasite to be detected. The high rate of parasitosis in endemic areas underlines the importance of lending greater attention to immigrant patients in Italy, due also to the fact that parasitosis is often found in asymptomatic forms.

[Intestinal parasitosis prevalence in outpatients and inpatients of Cã Granda IRCCS Foundation - Ospedale Maggiore Policlinico of Milan: data comparison between 1984-1985 and 2007-2009]

This paper evaluates the prevalence of intestinal parasitosis in a specific population over three years (2007-2009). The results were compared with published data collected from the same population in 1984-1985. During a survey from January 1st 2007 to December 31(st) 2009 a total of 2962 inpatients and outpatients were evaluated in our facility (IRCCS Foundation - Ospedale Maggiore Policlinico) for ova and protozoa stool examination (OPE) over three specimens collected alternatively for three days. 614 inpatients and outpatients were evaluated for the Graham Test (GT) over three slides collected for three days (day by day). Sixty inpatients and outpatients were also sampled for agar culture for detecting Strongyloides larvae in faeces. OPE revealed 13.26% of the patients positive for parasites; TG revealed 8.14% were positive. Overall, 16.66% of the patients were positive for Strongyloides larvae agar culture. Of the OPE trial group, only 4.2% were positive for real pathogen parasites. 1.78% of the total was affected by several parasites. Apart from the prevalence of Entamoeba histolytica/dispar and Taenia spp, which was unchanged, all other levels fell compared with the 1984 - 1985 results. New pathogens, namely Hymenolepis nana and Schistosoma mansoni, were detected during 2007-2009 period. Strongyloides stercoralis was the most frequently diagnosed helminth in 2007-2009 as in the previous time period.

Late onset pulmonary Lophomonas blattarum infection in renal transplantation: a report of two cases

Lophomonas blattarum, a rare protozoa, was involved in pulmonary infections of transplant recipients. We report 2 cases of late onset pulmonary L. blattarum infection in renal transplant recipients with normal graft function and relative normal immune function. The diagnosis in both cases was confirmed by bronchoscopy and broncho alveolar lavage (BAL) fluid examination. Both cases were sensitive to metronidazole treatment, but one case did not completely recover during the follow-up. The diagnosis and treatment were discussed to facilitate improvement in the recognition of this rare infection, especially in transplant recipients.

Is SELDI-TOF a valid tool for diagnostic biomarkers?

The genome revolution is providing fresh insights into host and parasite genomes, and new tools are becoming available for examining host-parasite interactions at the proteome level. Technologies such as surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry (MS) can be applied to discover biomarkers (alterations in both host and parasite proteomes) associated with parasitic diseases. Such biomarkers can represent host proteins, fragments of host proteins or parasite proteins that appear in body fluids or tissues following infection. Individual biomarkers or biomarker patterns not only have diagnostic utility (e.g. in active disease, prognosis, tests of cure) but can also provide unique insights into the mechanisms underlying host responses and pathogenesis.

Importance of nonenteric protozoan infections in immunocompromised people

There are many neglected nonenteric protozoa able to cause serious morbidity and mortality in humans, particularly in the developing world. Diseases caused by certain protozoa are often more severe in the presence of HIV. While information regarding neglected tropical diseases caused by trypanosomatids and Plasmodium is abundant, these protozoa are often not a first consideration in Western countries where they are not endemic. As such, diagnostics may not be available in these regions. Due to global travel and immigration, this has become an increasing problem. Inversely, in certain parts of the world (particularly sub-Saharan Africa), the HIV problem is so severe that diseases like microsporidiosis and toxoplasmosis are common. In Western countries, due to the availability of highly active antiretroviral therapy (HAART), these diseases are infrequently encountered. While free-living amoebae are rarely encountered in a clinical setting, when infections do occur, they are often fatal. Rapid diagnosis and treatment are essential to the survival of patients infected with these organisms. This paper reviews information on the diagnosis and treatment of nonenteric protozoal diseases in immunocompromised people, with a focus on patients infected with HIV. The nonenteric microsporidia, some trypanosomatids, Toxoplasma spp., Neospora spp., some free-living amoebae, Plasmodium spp., and Babesia spp. are discussed.

[Biology, epidemiology and diagnostics of pathogenic waterborne protozoan parasites]

Cryptosporidium, Giardia intestinalis, Cyclospora cayetanensis, Isosopra belli and micropsoridia are the most important and common pathogens found in humans and many other species of vertebrates. In humans, mainly in immunocompromised patients, children, pregnant women and elderly people, they are the most frequently identified protozoan parasites causing gastrointestinal disease worldwide. These pathogens have several transmission routes, including anthroponotic and zoonotic transmission. What is more, in many cases of epidemics caused by mentioned pathogens the major cause of infection was contaminated with these organisms water and food. In spite of many existing regulations of clearing and making use of drinking water supplies and recreational water, cosmopolitan protozoan parasites are still the danger of public health. These organisms are responsible for many waterborne outbreaks worldwide. Light microscopy and immunofluorescence assay have been used to identify these organisms in most laboratories. However, these traditional techniques have major limitations in the specific diagnosis, these methods are not sensitive enough to detect cysts or oocysts in environmental samples, so the new molecular tools must be applied. Recently, PCR-based techniques have been developed for detection and genetic characterization of the different species and population variants of protozoan parasites is central to the prevention, surveillance and control of gastrointestinal diseases. In this review were characterized biology, epidemiology and the progress in technology for detection and surveillance of the most important waterborne protozoan parasites.

[Protozoons and arthropods found in eyes]

Protozoons and arthropods can be observed commonly all around the world including our country. These parasites can cause different kind of disorders in human and animals. Some of these can cause eye disorders. The aim of this review was to present information about how the protozoons such as Toxoplasma gondii, Leishmania spp., Trypanosoma spp., Giardia spp., Acanthamoeba spp., Plasmodium spp., the arthropods insects of myiasis, Phthirus pubis, ticks, Demodex folliculorum and Linguatula serrata (under discussion as to which order it beongs) invade the eye of host leading to clinical symptoms, diagnosis and treatment.

Clinical significance of enteric protozoa in the immunosuppressed human population

Globally, the number of immunosuppressed people increases each year, with the human immunodeficiency virus (HIV) pandemic continuing to spread unabated in many parts of the world. Immunosuppression may also occur in malnourished persons, patients undergoing chemotherapy for malignancy, and those receiving immunosuppressive therapy. Components of the immune system can be functionally or genetically abnormal as a result of acquired (e.g., caused by HIV infection, lymphoma, or high-dose steroids or other immunosuppressive medications) or congenital illnesses, with more than 120 congenital immunodeficiencies described to date that either affect humoral immunity or compromise T-cell function. All individuals affected by immunosuppression are at risk of infection by opportunistic parasites (such as the microsporidia) as well as those more commonly associated with gastrointestinal disease (such as Giardia). The outcome of infection by enteric protozoan parasites is dependent on absolute CD4(+) cell counts, with lower counts being associated with more severe disease, more atypical disease, and a greater risk of disseminated disease. This review summarizes our current state of knowledge on the significance of enteric parasitic protozoa as a cause of disease in immunosuppressed persons and also provides guidance on recent advances in diagnosis and therapy for the control of these important parasites.

Molecular characterization of a new Tetratrichomonas species in a patient with empyema

A new Tetratrichomonas species was identified by molecular and phylogenetic approaches in the pleural fluid from a patient with encysted empyema leading to dyspnea. This observation raised the questions of the real prevalence of pulmonary trichomonosis in humans, the zoonotic potential of trichomonads, and the existence of human-host-adapted strains.

Tropical dermatology: Tropical diseases caused by protozoa

Protozoan infections are very common among tropical countries and have an important impact on public health. Leishmaniasis is the most widely disseminated protozoan infection in the world, while the trypanosomiases are widespread in both Africa and South America. Amebiasis, a less common protozoal infection, is a cause of significant morbidity in some regions. Toxoplasmosis and pneumocystosis (formerly thought to be caused by a protozoan) are worldwide parasitic infections with a very high incidence in immunocompromised patients but are not restricted to them. In the past, most protozoan infections were restricted to specific geographic areas and natural reservoirs. There are cases in which people from other regions may have come in contact with these pathogens. A common situation involves an accidental contamination of a traveler, tourist, soldier, or worker that has contact with a reservoir that contains the infection. Protozoan infections can be transmitted by arthropods, such as sandflies in the case of leishmaniasis or bugs in the case of trypanosomiases. Vertebrates also serve as vectors as in the case of toxoplasmosis and its transmission by domestic cats. The recognition of the clinical symptoms and the dermatologic findings of these diseases, and a knowledge of the geographic distribution of the pathogen, can be critical in making the diagnosis of a protozoan infection.

LEARNING OBJECTIVES

After completing this learning activity, participants should be able to recognize the significance of protozoan infections worldwide, identify the dermatologic manifestations of protozoan infections, and select the best treatment for the patient with a protozoan infection.

High prevalence of Microsporidium infection in HIV-infected patients

Sixty-four patients infected with human immunodeficiency virus (HIV) participated in a study to determine opportunistic enteric pathogens and compare them with the patients' clinical status. The most frequently found pathogens were microsporidium (81.2%), Cryptosporidium parvum (20.3%), Candida albicans (12.5%) and Blastocystis hominis (10.9%). Less frequently found pathogens were Giardia intestinalis (6.2%), Cyclospora (4.7%), Opishorchis viverrini ova (3.1%), Strongyloides stercoralis larvae (3.1%) and hookworm ova (1.6%). The presence of enteric pathogens was not significantly associated with sex, length of HIV seropositivity and diarrheal symptoms. A high prevalence of microsporidium, based on microscopic examination, was found in Thai HIV-infected patients. This confirms the importance of microsporidium in HIV-infected/AIDS patients and the necessity for stool evaluation in all HIV-infected patients.

Chronic intermittent diarrhea in a 14-month-old Abyssinian cat

A 14-month-old intact, female Abyssinian cat was presented for chronic intermittent diarrhea and bilateral enlargement of the mammary glands. Gastrointestinal coccidiosis was diagnosed; therapy with sulfadi-methoxine was unsuccessful in the elimination of Isospora felis and clinical signs. Infection with Tritrichomonas foetus was diagnosed by fecal polymerase chain reaction (PCR) and successfully treated with ronidazole and dietary modification.

Frequency of enteric protozoan parasites among patients with gastrointestinal complaints in medical centers of Zahedan, Iran

We investigated the prevalence of intestinal protozoan parasites in patients with gastrointestinal complaints in medical centers in Zahedan, Iran. A total of 1562 stool samples was examined from July 2004 to January 2006 using microscopy (direct smear, formalin-ether concentration), xenic culture and PCR techniques. Four hundred and twenty-seven (27.3%) of the patients were infected with one or more intestinal parasites. Giardia lamblia (10.1%), Entamoeba coli (10%), E. hartmanni (1.7%), Blastocystis hominis (2.2%), Chilomastix mesnili (1.7%), Trichomonas hominis (0.7%), E. histolytica/E. dispar (0.51%) and Iodamoeba butschlii (0.45%) were the most prevalent protozoa detected with microscopy. Of the eight microscopy-positive E. histolytica/E. dispar samples, six were identified as E. dispar by PCR/gel electrophoresis, whereas E. histolytica was not detected at all. Although Zahedan is an area with poor hygiene located in a tropical area near the border of Pakistan and Afghanistan, the prevalence of E. histolytica and E. dispar here compared with other parasites and infectious diseases is unexpectedly low.

[Bronchopulmonary Lophomonas blattarum infection: two cases report and literature review]

OBJECTIVE

To improve the recognition and diagnosis of pulmonary Lophomonas blattarum infection.

METHODS

Two cases of bronchopulmonary Lophomonas blattarum diagnosed in this hospital were reported. The clinical features of 13 cases in the literature during the period of 1993 to 2006, 1 case with sinus infection and 12 cases with bronchopulmonary infection, were also analyzed.

RESULTS

For the 2 cases diagnosed in this hospital, severe asthma and bronchiectasis with prolonged infection were the underlying diseases, respectively. The diagnosis of these 2 cases and the 13 cases reported in the literature were all confirmed by the presence of parasites in airway samples. The most common symptoms included fever (64.3%), cough and expectoration (71.4%). Fifty percent of the patients showed increased eosinophils in peripheral blood. Chest radiograph and CT scan showed changes similar to pneumonia (83.3%). Chronic cases were manifested with asthma attack, bronchiectasis or lung abscess. Smear preparations of sputum or specimen by bronchoscopy were direct methods for diagnosis.

CONCLUSION

Pulmonary Lophomonas blattarum infection is an emerging infectious disease caused by protozoon of hypermastigote parasitized in the bronchus or the lung. Epidemiological characteristics including host, route of transmission and susceptible population of Lophomonas blattarum infection are not fully understood. The optimal treatment also needs further investigation.

Development of a diagnostic PCR to detect Neoparamoeba perurans, agent of amoebic gill disease

The recent description of Neoparamoeba perurans as an aetiological agent of amoebic gill disease (AGD) advanced our understanding of the condition and has forced a re-evaluation of methods used for the diagnosis of AGD. Currently, there are no tools available that are both specific for N. perurans and suitable for a routine diagnostic procedure. Therefore, in this study we describe an assay to detect N. perurans. The assay, which utilizes PCR to amplify the N. perurans 18S rRNA gene, was shown to be specific and highly sensitive. Neoparamoeba perurans was detected in both gill samples and primary isolates of non-cultured gill-derived amoebae obtained during necropsy or biopsy from AGD-affected Atlantic salmon, Salmo salar L. The PCR-based assay provides a simple, flexible tool that will be a useful addition to the diagnostic repertoire for AGD. It may also be used for the genotypic screening of trophozoites during culture and could facilitate further epidemiological and ecological studies of AGD.

[Diagnosis and treatment of major protozoal infections among acquired immune deficiency syndrome patients]

Protozoal infection is one of the most important opportunistic infections among patients with acquired immune deficiency syndrome (AIDS). In order to enhance the knowledge of protozoal infections in AIDS, the current status of diagnosis and treatment of toxoplasmic encephalitis, cryptosporidiosis, microsporidiosis and isosporiasis was reviewed in this paper.

[Diagnosis of intestinal-protozoa in patients with immune deficiency]

In our study, we tried to detect gastroenteritis causing intestinal protozoa in patients with immune deficiency and who suffered from diarrhea. We also tried to determine which laboratory methods should be used in detecting intestinal protozoon in these patients. Thirty-six immune deficient patients who had had diarrhea for more than 10 days and 44 immune deficient patients without diarrhea were included in the study. In stool samples taken from all cases, intestinal protozoa were detected using the conventional diagnostic methods including direct wet mount, trichrome and modified acid fast staining as well as serologic diagnostic methods such as ELISA, direct fluorescent antibody (DFA)] and the molecular method of polymerized chain reaction. In our study, we found that intestinal protozoan such as G. intestinalis; C. parvum, B. hominis and E. histolytica could be responsible for the long term diarrhea in patients with immune deficiency. If a pathogen is not detected in the feces by native Lugol (NL), DFA and MAF are suitable techniques for Cryptosporidium spp while ELISA or trichrome staining are suitable methods for E. histolytica. It was concluded in the study that the simple and inexpensive NL method is sufficient in the diagnosis of G. intestinalis and serological or molecular methods are unnecessary. Neutropenia in patients with immune deficiency did not enhance the frequent occurrence of intestinal protozoan infections; and also, in the cases with immune deficiency, it was found that the administration of steroid treatment was not a risk factor in intestinal protozoan disease.

Disseminated Balamuthia mandrillaris amoeba infection in an AIDS patient from Brazil

This report describes a 32-year-old male AIDS patient. He presented with a clinical picture characterized by severe headache, blurred vision, and fever that had lasted for 10 days. At admission, no remarkable neurologic abnormalities were observed. Cranial tomography showed a ring-enhanced lesion with edema and a mass effect in the right occipital lobe. The initial diagnosis was toxoplasmosis, and treatment of this was administered. However, 5 days later, the patient's clinical status worsened and he died. The necropsy showed necrotizing and hemorrhagic encephalitis, with trophozoites similar to an amoeba species. Furthermore, the kidneys, adrenal glands, thyroid gland, and liver were also involved. The amoeba Balamuthia mandrillaris was identified by an immunofluorescence test.

First record of natural Tritrichomonas foetus infection of the feline uterus

Tritrichomonas foetus was found in the uterus of a cat with pyometra and in the faeces of three other cats in the same household, one of which had chronic diarrhoea. This is the first report of a feline uterine infection with T. foetus and also the first time T. foetus has ever been diagnosed in animals in Norway. The diagnosis was made by microscopic examination and sequencing studies.

Sensitivity and specificity of culture and PCR of smegma samples of bulls experimentally infected with Tritrichomonas foetus

The sensitivity (Se) and specificity (Sp) of different testing schemes were estimated for detecting Tritrichomonas foetus (T. foetus) in smegma samples from experimentally infected bulls. Culture and polymerase chain reaction (PCR) on smegma samples were evaluated alone and in parallel testing. Mature dairy bulls (n=79) were intrapreputially inoculated with T. foetus (n=19); Campylobacter (C.) fetus venerealis (n=13); both T. foetus and C. fetus venerealis (n=11); Tetratrichomonas spp. (n=9); C. fetus fetus (n=8); or were not inoculated (n=19). For each bull, smegma samples were collected for 6 week post-inoculation and tested for T. foetus by In Pouch TF culture and PCR. Most T. foetus-inoculated bulls became infected, according to culture (86.7%), PCR (90.0%), and both tests together (93.3%). In T. foetus-inoculated bulls, both tests combined in parallel on a single sample had a Se (78.3%) and Sp (98.5%) similar to two cultures (Se 76.0%, Sp 98.5%) or two PCR (Se 78.0%, Sp 96.7%) sampled on consecutive weeks. The PCR on three consecutive weekly samples (Se 85.0%, Sp 95.4%) and both tests applied in parallel on three consecutive weekly samples (Se 87.5%, Sp 95.6%) were similar to the current gold-standard of six weekly cultures (Se 86.7% and Sp 97.5%). Both tests used in parallel six times had the highest Se (93.3%), with similar Sp (92.5%). Tetratrichomonas spp. were only sporadically detected by culture or PCR. In conclusion, we have proposed alternative strategies for T. foetus diagnostics (for the AI industry), including a combination of tests and repeat testing strategies that may reduce time and cost for bull surveillance.

Intestinal parasitic infection among children and neonatus admitted to Ibn-Sina Hospital, Sirt, Libya

A total of 350 stool samples from 196 males and 154 female children and neonatus admitted in Ibn-Sina hospital, Sirt, were examined from June 2001 to May 2002, to determine the prevalence of intestinal parasites. Intestinal parasitic infections were identified in 196 (56%) of children and neonates. No intestinal helminthic parasites were detected but 13 intestinal protozoan parasites were detected. The most prevalent protozoan was Entamoeba histolytica /E. dispar (36.57%); Blastocystis hominis (12.57%), Giardia lamblia (10.29%), Isospora belli (3.14%) and Balantidium coli (0.86%), the latter was detected in non-Libyan children. The non-pathogenic ones were Entamoeba coli (15.14%), Endolimax nana (13.71%), Entamoeba hartmanni (4.29%), Chilomastix mesnilli (4.29%), Retortamonas intestinalis (3.43%), Dientamoeba fragilis (2%), Iodamoeba butschlii (0.86%) and Trichomonas hominis (0.86%). The result showed a significant difference exists between the prevalence of pathogenic and non-pathogenic protozoan parasites (P < 0.05). High prevalence of E. histolytica/ E. dispar followed by E. coli, E. nana, B. hominis and G. lamblia in both sexes of children, while the prevalence of other intestinal parasites were low in both sexes, significantly different existed in the prevalence of intestinal parasites between males and females children (t = 24.68; P < 0.05). Age groups had no effect on the prevalence of intestinal parasites (F = 0.66; P < 0.05). Significant differences existed in the prevalence between single and multiple infections with pathogenic protozoa. The socio-economic status of children parents revealed that high prevalence in children from medium socio-economic status. The family size had no significant effect on the prevalence of the intestinal parasites.